I originally posted this at http://www.318.com/TechJournal
Mailbfr, spamtrainer and amavis-stats are great packages that fit into Mac OS X Server. The guys from topicdesk have been kind enough to post an overview on how their products work under Leopard and how the changes in Leopard impact their utilization. Check it out at:
http://osx.topicdesk.com/content/view/129/1/